1. Field of the Invention
The present invention relates to a method for applying a solder resist layer into a printed conductor pattern of a printed circuit board, particularly a three-dimensional printed circuit board, while leaving plated-through holes and/or solder pads free.
2. Description of the Prior Art
In the manufacture of printed circuit boards, a solder resist layer should be applied onto those regions of the printed conductor pattern that should not enter into a solder connection, this being carried out after the structuring of the printed conductor pattern. The solder resist layer only leaves plated-through holes and/or solder pads free, so that an ultimate solderable surface can be produced thereat by hot tinning or by a remelting process. The application of the solder resist layer can thereby be undertaken by selective application of a solder resist onto the regions to be protected or by a surface-wide application of a light-sensitive solder resist having subsequent photostructuring. Selective application thereby involves too much expense, whereby the photostructuring cannot be implemented with traditional masks techniques, particularly given three-dimensional printed circuit boards.